BACKGROUND: Improving quality of life (QoL) is important for the treatment of people with bipolar disorder (BD). Early-BipoLife is a German multicentre naturalistic, prospective-longitudinal observational cohort study investigating early recognition and intervention in people at increased risk of developing a BD. This analysis aims to investigate influencing factors and changes in QoL as a basis for the development of early intervention strategies in patients with at risk syndrome for BD. METHOD: A cohort of 1086 participants (15-35 years) with at least one risk factor (EPIbipolar criteria) for BD was assessed over the course of 2 years. Changes in QoL (WHOQOL-BREF) were evaluated in a mixed model for repeated measures. RESULTS: Compared to an age-matched comparison group, people at risk for BD showed significant lower QoL in all domains at baseline. The overall QoL of the psychological well-being domain of the WHOQOL-BREF increased over the 2 year study course (p <
0.001). The bipolar risk group (EPIbipolar) change from baseline divided into (a) decreasing, (b) increasing and (c) constant risk group in the course of 2 years. Baseline risk group assignment was not a significant predictor of change in QoL over 2 years for any of the QoL domains, but participants with an increase in risk over the 2-year course had a significantly smaller gain in QoL than the group with constant risk (p = 0.014) or decreasing risk (p <
0.001). Higher levels of QoL were associated with a higher self-rated ability to use coping strategies. Moreover, a higher level of functioning (GAF) at baseline was positively correlated with improvement of different QoL domains after 2 years. CONCLUSION: Patients with a risk syndrome for BD reported significantly reduced QoL compared to their age-matched comparison group. Risk status monitoring might be beneficial to identify individuals who could profit from an intervention to increase their QoL. Further studies promoting the development of coping strategies for successful self-management could be helpful to improve overall mental health and positively influence QoL.